Dyeing properties of cotton fibres treated with liquid ammonia

Both scoured and sodium hydroxide mercerised cotton fibres have been treated with liquid ammonia atndash33.4°C using commercial operating equipment and then the ammonia removed at 130°C in a hot drum. The moisture regain and water absorbency of the fibres treated with liquid ammonia were increased compared with values on untreated fibres, whereas both these parameters on mercerised cotton fibres were decreased by subsequent liquid ammonia treatment. The fibres were dyed with CI Direct Red 2 and CI Direct Blue 1. Liquid ammonia treatment of the scoured cotton fibres increased the rate of dyeing, equilibrium dye adsorption, standard affinity, heat of dyeing and change of entropy, while the dyeing properties of mercerised cotton were adversely affected by subsequent liquid ammonia treatment.     

Dyeing behaviors of ionic liquid treated wool

In this article, a new class of “green” solvent—ionic liquid (IL) was employed to improve the dyeability of wool. The physical and chemical properties of the IL‐treated wool, such as surface morphology, wettability, and tensile strength were first analyzed, and then the dyeing properties of IL‐treated wool were investigated in terms of dyeing rate, dyeing exhaustion at equilibrium, color depth, and color fastnesses. The scanning electron microscope (SEM) images showed eroded marks on IL‐treated wool fiber surfaces. The water contact angle of the fabric treated with IL at 100°C decreased from 118.6° to 106.4°. The tensile strength of IL‐treated wool fibers was slightly decreased when the treating temperature was less than 100°C. Dyeing kinetics experiments revealed that the IL treatments greatly increased initial dyeing rate, shortened half‐dyeing time, and time to reach dyeing equilibrium. The final exhaustion and color depth of IL‐treated wool were also increased accompanying with slightly decreased color fastness. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Colorimetric properties of wool dyed with natural dyes after treatment with ammonia

An evaluation has been carried out of the effect of ammonia on the colouristic properties of wool dyed with a range of natural dyes containing anthraquinone, naphthaquinone, flavone and tannin structures. It was found in all cases that after-treatment with ammonia caused a decrease in the lightness ( L *) values. The reasons for this are discussed, as is the fact that the colour change is not reversible on subsequent treatment with acid.     

Dyeing wool packages with continuous dosage of dye

Integration dyeing of wool packages by Lanaset dyes has been examined. Absorption kinetics were found to be governed by the Cegarra-Puente equation, giving an apparent activation energy of 104 kJ/mol. The levelness obtained by integration dyeing at various temperatures and dye concentrations were compared with that obtained by following the standard method. Similar values were observed in both systems.     

Dyeing of wool with temporarily solubilised disperse dyes

Temporarily solubilised disperse dyes derived from aminophenyl-4-(β-sulphatoethylsulphone) have been applied to wool fabric without the use of a levelling agent. By virtue of their characteristic dye structure, excellent levelling properties were observed on wool fabric. Good exhaustion, fixation and fastness test values were also obtained.     

Dyeing kinetics of wool fabrics pretreated with a protease

Dyeing kinetics of wool fabrics treated with different concentrations of an enzyme of the protease type are studied in this work. Dyeing isotherms with an acid and a premetalised 2:1 dyestuff were carried out and the fit of several kinetic equations to the experimental results determined. The absorption rate constants and activation energies were calculated.     

Gasification of coals treated with non-aqueous solvents. 5. Properties of coals treated with liquid ammonia

Five coals of various ranks were treated with liquid ammonia at 373 K and 10 MPa, and some properties were examined. Although the equilibrium pore volume accessible to carbon dioxide was not affected, the rate of adsorption increased remarkably upon treatment. The pore volume determined by a larger molecule, say hexane, also increased greatly. When a nickel salt was impregnated among the coal surfaces, more satisfactory results were obtained on the treated coal. The treated coals were more easily comminuted than the parent coals. The relation between the change of these properties and the gasification reactivity is discussed.     

Gasification of coals treated with non-aqueous solvents. 4. Reactivity of coals treated with liquid ammonia

Gasification rates of twelve coals treated with liquid ammonia and impregnated with nickel were measured in hydrogen and in steam, and the effects of the ammonia treatment were compared. The treatment was found to promote gasification of most bituminous coals, especially the higher-caking coals. The increases in reactivity relative to untreated specimens were larger for gasification with hydrogen at 1273 K than for those with steam at 1125 K, but the trends with coal rank were similar. From a correlation found between the reactivities and the degree of degradation of the coal particles caused by the ammonia treatment, it was inferred that the treatment affected their pore structure.     

Dyeing properties of oxygen low-temperature plasma-treated wool and nylon 6 fibres with acid and basic dyes

Wool and nylon 6 fibres treated with oxygen low-temperature plasma were dyed with acid and basic dyes. Despite the increase of electronegativity of the fibre surface caused by the plasma treatment, the rate of dyeing of wool was increased with both dyes, while that of nylon 6 was decreased with the acid dye and increased with the basic dye.     

Dyeing transition temperature of wools treated with low temperature plasma,liquid ammonia,and high‐pressure steam in dyeing with acid and disperse dyes

Wool fibers treated with oxygen low‐temperature plasma, liquid ammonia (NH₃), and high‐pressure (HP) steam were dyed with two acid and three disperse dyes. Rate of dyeing, saturation dye uptake, and dyeing transition temperature were measured. Rate of dyeing of the O₂ plasma, NH₃, and HP steam‐treated wools increased with acid dyes, whereas it did not increase with disperse dyes. Although dyeing transition temperature for acid dyes was decreased by the plasma, NH₃, and HP steam treatments, the temperature for disperse dyes was not changed by the treatments. Therefore, it seems that acid dyes penetrate by the intercellular diffusion through the interscale Cell Membrane Complex (CMC) of wool, whereas disperse dyes penetrate by the intracellular diffusion through the intrascale cuticle surface independently with CMC relaxation by the treatments. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1058–1062, 2001     

Evaluation of some of the properties of plasma treated wool fabric

Low temperature plasma (LTP) treatment was applied to wool fabric with the use of a nonpolymerizing gas, namely oxygen. Properties of the LTP‐treated samples including low stress mechanical behavior, air permeability, and thermal characteristics were evaluated in this study. Kawabata evaluation system fabric (KES‐F) was employed to determine the tensile, shearing, bending, and compression strength properties and surface roughness of the specimens. The changes in these properties are believed to be closely related to the interfiber and interyarn frictional force induced by the LTP. The decrease in the air permeability of the LTP‐treated wool fabric was found to be probably because of the plasma action effect on increasing the fabric thickness and a change in fabric surface morphology, which was confirmed by scanning electron microscopy micrographs. The change in the thermal properties of the LTP‐treated wool fabric was in good agreement with the earlier findings and can be attributed to the amount of air trapped between the yarns and fibers. This study suggested that the LTP treatment can influence the final properties of the wool fabric, and also provide information for developing LTP‐treated wool fabric for industrial use. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5958–5964, 2006     

Improving the dyeing properties of textiles via utilization of redox systems. I. Dyeing of wool and wool/polyacrylic blend fabrics with acid dye

Dyeing of wool and wool/polyacrylic fabrics with an acid dye, namely, Kiton Scarlet 4 R, was carried out in absence or presence of different redox systems. The latter were based on sodium, potassium, or ammonium peroxodisulphate or potassium periodate as oxidant and glucose, sodium thiosulphate, potassium pyrosulphite or thiourea as reductant. Regardless of the redox system used, the colour strength was far greater in presence than in absence of the redox system. Except in case of potassium periodate/glucose redox system, increasing the oxidant concentration up to 0.03 mol/l caused significant enhancement in colour strength. The same was observed upon increasing the temperature from 30 to 60°C as well as the time from 10 to 40 minutes. It is postulated that presence of the redox system alters the mode of dye attachment to the substrate. Association of the dye with the substrate, wool in particular, seems to involve covalent bonding beside the usual salt-linkage. Hence the approach presented is advantageous in producing dyeings with much higher colour strength and dye fixation at relatively low temperature.     

羊毛角蛋白液涂覆处理涤纶的亲水性研究

利用三羧乙基膦(TCEP)和亚硫酸氢钠溶解羊毛制备羊毛角蛋白溶液;采用羊毛角蛋白液涂覆处理涤纶,改善涤纶的亲水性,结果表明:采用体积分数为10%的羊毛角蛋白液涂覆处理涤纶织物,织物平均增重率大于9%,织物的回潮率由0.57%提高到7.16%.吸湿性明显改善;采用TG酶交联角蛋白液涂覆处理织物,可改善其耐洗性;TC酶交联角蛋白的最佳工艺为:TG酶用量1 g,交联时间5 h,交联液pH值为7;经扫描电镜观察和X射线光电子能谱分析,羊毛角蛋白对涤纶有很好的粘附     

Dyeing of polyamide—wool fibre blend with acid dyes using α-cyclodextrin

The colors of polyamide fibre obtained in dyeing with α-cyclodextrin (CD) additive are uniform and saturated. This effect is also obtained on wool fibre and wool—polyamide fibre blend. It was found that the dyeability of the samples with α-CD is much higher than for samples without the additive with an increase in the temperature. In spectrophotometric determination of complexation in the dye—α-CD aqueous system, it was found that the dyeability of the samples was highest in a 1:1 ratio than with the standard dyeing method. α-CD thus acts as a process booster. __________ Translated from Khimicheskie Volokna, No. 3, pp. 37–39, May–June, 2007.     

Fabric properties of butadienediepoxide-treated cottons as affected by liquid ammonia pretreatments

Effects of liquid ammonia and mercerizing-strength caustic as pretreatments upon textile properties of cotton sheeting modified with butadienediepoxide (BDO) catalyzed by 2% and 15% NaOH were compared. Tensile properties of the NaOH-mercerized control (CM) (celluloses I and II) greatly exceeded those of native (cellulose I) and ammonia-treated (NH₃) controls. NH₃(I) and NH₃(III) are those cottons having the cellulose I and mixed cellulose I and III lattices, respectively. Resistance to flex abrasion was doubled by pretreatments. Wrinkle recoveries of all controls were equivalent, but tensile recovery differed. BDO reaction enhanced wrinkle recovery of controls but produced the usual losses in tensile properties and resistance to flex abrasion associated with crosslinking reagents. BDO reaction nullified the initial tensile advantage held by CM cotton. Tear strengths of all BDO-treated cottons remained comparable. High dry and high wet recoveries were obtained only when 2% NaOH catalyzed the BDO reaction and were greatest for NH₃ cottons. BDO reaction reduced permanent set of all controls and increased tensile recovery primarily by enlarging the delayed recovery. Postmercerization with 23% NaOH adversely affected recovery behavior of all BDO-treated cottons. Nevertheless, wrinkle and tensile recoveries of postmercerized NH₃(I) and CM cottons were equivalent. Postmercerization partially restored fabric properties of BDO cottons with cellulose I lattice to those of their respective controls; no change was noted for corresponding products from CM cottons. Because of this, final properties of products from NH₃(I) cottons equaled and even exceeded those of comparable CM cottons.     

Surface modification and low temperature dyeing properties of wool treated by UV radiation

The surface modification and dyeing properties of wool treated by UV radiation have been investigated. Wool samples were exposed to UV radiation for 60 min and the surface modification of the wool fibre was investigated by X-ray photoelectron spectroscopy. The chemical change caused by the UV treatment was identified as surface oxidation of cystine (disulphide bonds) and thereby induced changes in the dyeing properties of the wool. The dyeability of UV-treated and untreated wool samples was determined at temperatures of 45, 50, 55 and 60 °C using CI Acid Blue 7. The UV-treated wool samples showed greater levels of dye uptake compared with those of the untreated samples. The adsorption behaviour and diffusion coefficients were also studied. The dyeing properties of wool were enhanced by UV radiation due to the increased diffusion coefficient of the dyes in the treated wool fibres.     

Silver-coated wool yarns with durable antibacterial properties

The use of fabrics with antibacterial properties for commodity applications can provide numerous advantages such as a reduction in the release of odors due to bacterial proliferation in sweat and a reduction in the development of skin hypersensitivity reactions due to microorganisms trapped into the fabrics. Silver is one of the most effective antibacterial agents used for the high degree of biocompatibility and for its long-term antibacterial effectiveness against many different bacterial strains. In this study, an innovative technique for the deposition of nanosilver antibacterial coating on woolen fiber was analyzed. In particular, fabrics woven with different percentages of silver-treated fibers were compared to determine the best ratio preserving the antibacterial activity and optimizing the cost-effectiveness of the final product. Scanning electron microscopy revealed a uniform distribution of silver nanoclusters on the fibers. The impressive silver coating stability and durability were demonstrated after several washing cycles through thermogravimetric analysis. The antimicrobial activity of the silver-treated substrates was evaluated by antibacterial tests on Escherichia coli. A very strong antibacterial activity was found even in presence of the lower silver content; therefore, a blend of coated and uncoated fibers is proposed for practical applications. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effect of mode of agent removal on pore structure of liquid ammonia treated cotton cellulose

The pore structures of three liquid-ammonia-treated cottons were compared via a reverse gel permeation chromatographic technique. Cotton battings were treated with liquid ammonia which was removed by volatilization at ambient temperature or at elevated temperature and by water exchange. Three series of water-soluble solutes were used to study the elution characteristics of whole fiber columns prepared from these battings. The solutes were oligomeric sugars, ethylene glycols, and glymes (ethylene glycol dimethyl ethers) having molecular dimensions in the range of conventional finishing agents for cotton. All three liquid ammonia treatments increased the internal pore volumes accessible to small molecules. The greatest increase was noted when the ammonia was removed by water exchange and the least when volatilization at elevated temperature was employed. Ambient temperature volatilization had an intermediate effect. Decreases in the volumes of large pores were effected by ammonia treatments followed by volatilization at ambient or elevated temperature. Water exchange of the ammonia resulted in an increase in the volume of large pores as well as of the small pores.     

Dyeing properties of polyamide super-microfibre with disperse dyes

The dyeing properties of polyamide super-microfibres and conventional fibres dyed with disperse dyes have been studied by measuring the adsorption isotherm, the rate of dye uptake, the time of half-dyeing and the amount of equilibrium adsorption. The thermodynamic analysis shows that the adsorption isotherms of super-microfibres follow a Langmuir sorption model. The kinetic results show that super-microfibres have a faster dyeing rate and a higher equilibrium dye uptake compared to conventional fibres. This can be explained by the greater surface area and dye capacity of the super-microfibres. The wash and light fastness properties of the super-microfibres dyed with disperse dyes are lower than conventional fibres.     

Dyeing behaviour of Japanese oak silk fibres treated with methacrylamide

Japanese oak silk fibres have been treated with methacrylamide, and the dyeing behaviour when using levelling acid and milling acid dyes has been investigated. Infra-red spectroscopy indicated that a methacrylamide polymer skin was produced on the fibre surface at high levels of polymer add-on. The methacrylamide polymer skin was dyed with the milling acid dye, although not dyed with the levelling acid type. The penetration of the levelling acid dye into the fibres was not interrupted by the polymer skin.